A graphics engine, graphics processing unit (GPU), or visual processing unit (VPU), is a specialized electronic circuit designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer typically intended for output to a display. GPUs may be found in embedded systems, mobile phones, tablets, notebook computers, high performance computation (HPC) servers, and game consoles. In addition to manipulating computer graphics, a highly parallel architecture also enables a GPU to more generally perform processing of large blocks of video stream and image data in parallel.
Video streaming and display devices are now ubiquitous in electronic media. With the rapid development of image and video display devices, the colors and images can be received, manipulated, and reproduced in a variety of color gamuts. Such video/image data are often exchanged between devices having differing output display color gamuts. A device with narrower color gamut that simply clips all values outside the available display gamut may cause loss of details and a reduction in the sense of depth that reduces image quality and disrupts a user's viewing experience. Mapping between color gamuts of differing size (e.g., compression of pixel color values within a wider gamut to a narrower gamut) has therefore become an important function in graphical media processing.
International Color Consortium (ICC) color management defines a limited set of controls for gamut mapping while leaving the user to adjust the original image to fit their final aesthetic goal. These are formally defined as rendering intents which includes four general categories of gamut mapping: (a) Perceptual, which maps all colors smoothly into the target gamut, although those outside of the target gamut will move relatively more than those inside; (b) Saturated, which maintains relative saturation values of colors; (c) Relative colorimetric, which is a minimal color transformation that usually projects out-of-gamut colors to the gamut surface with little or no mapping of in-gamut colors; and (d) Absolute colorimetric, which matches measured value to measured value without aligning the neutral axes.
Gamut mapping/compression methods and systems covering one or more of the gamut mapping categories, which for example may be implemented within a device GPU, may improve user experience and therefore add significant value and functionality to a host electronic media device.